Electrophotographic carrier and use thereof

Abstract

The present invention provides an electrophotographic carrier which includes a core particle, a first resin layer containing a charge-generating material for coating the core particle, and a second resin layer containing a hole-transporting material for coating the first resin layer. The invention also provides a two-component developer comprising said carrier, and an image-forming process and apparatus using said developer. According to the invention, high quality images can be formed, with excellent image density (especially when developing solid images) and less fogging.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is related to Japanese Patent Application No. 2008-167402 filed on Jun. 26, 2008, whose priority is claimed under 35 USC §119, the disclosure of which is incorporated herein in its entirety by reference for any and all purposes.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to an electrophotographic carrier, a two-component developer comprising the carrier, and an electrophotographic image-forming process and apparatus using said developer. In particular, the invention relates to an electrophotographic carrier comprising a core particle and resin layers for coating the core particle, a two-component developer comprising the carrier, and an image-forming process and apparatus, such as copiers, printers, facsimile machines and the like, using said developer.[0004]2. Description of the Related Art[0005]In electrophotographic image-forming apparatuses, generally, an image is forme...

AI Technical Summary

Benefits of technology

The present invention provides an electrophotographic carrier that can produce high-quality images with good image density, especially for solid images, while reducing fogging. The carrier has a core particle, two layers of resin containing a charge-generating material and a hole-transporting material, and a two-component developer containing the carrier and negatively chargeable toner. The invention also provides an image-forming apparatus and process using the carrier and developer. The technical effects of the invention are improved image quality and reduced fogging.

Problems solved by technology

However, they have a problem of being difficult to charge toner stably, etc.

On the other hand, since two-component developers need to be stirred before use in order to homogeneously mix toner and carrier, they have a problem that developing devices used therefor have a complicated structure with a mixer or the like.

Thus, they have a problem that, when used for developing solid images, the image density can be decreased.

However, such a coated carrier has a problem that the decreased carrier resistance makes it easier for electric charge to transfer from the photoconductor drum surface to the carrier so as to erase the latent image on the drum surface, and / or for the carrier to travel onto the drum surface so as to cause blurring or fogging in the formed images.

Images